International conference on the healthy effect of virgin olive oil

1. Ageing represents a great concern in developed countries because the number of people involved and the pathologies related with it, like atherosclerosis, morbus Parkinson, Alzheimer's disease, vascular dementia, cognitive decline, diabetes and cancer. 2. Epidemiological studies suggest that a Mediterranean diet (which is rich in virgin olive oil) decreases the risk of cardiovascular disease. 3. The Mediterranean diet, rich in virgin olive oil, improves the major risk factors for cardiovascular disease, such as the lipoprotein profile, blood pressure, glucose metabolism and antithrombotic profile. Endothelial function, inflammation and oxidative stress are also positively modulated. Some of these effects are attributed to minor components of virgin olive oil. Therefore, the definition of the Mediterranean diet should include virgin olive oil. 4. Different observational studies conducted in humans have shown that the intake of monounsaturated fat may be protective against age-related cognitive decline and Alzheimer's disease. 5. Microconstituents from virgin olive oil are bioavailable in humans and have shown antioxidant properties and capacity to improve endothelial function. Furthermore they are also able to modify the haemostasis, showing antithrombotic properties. 6. In countries where the populations fulfilled a typical Mediterranean diet, such as Spain, Greece and Italy, where virgin olive oil is the principal source of fat, cancer incidence rates are lower than in northern European countries. 7. The protective effect of virgin olive oil can be most important in the first decades of life, which suggests that the dietetic benefit of virgin olive oil intake should be initiated before puberty, and maintained through life. 8. The more recent studies consistently support that the Mediterranean diet, based in virgin olive oil, is compatible with a healthier ageing and increased longevity. However, despite the significant advances of the recent years, the final proof about the specific mechanisms and contributing role of the different components of virgin olive oil to its beneficial effects requires further investigations.

Carotid plaque morphology and cerebrovascular events

AIM

Beside the degree of stenosis, plaque morphology obtained by the B mode ultrasound technique has been considered to define the plaque at risk for cerebrovascular events, and a subset of patients who deserve more strict surveillance. Our aim was to evaluate the relationship between plaque morphology, progression of stenosis, and the development of new cerebrovascular events.

METHODS

We followed up by carotid duplex scan 230 asymptomatic patients, evaluating the degree and progression of internal carotid (ICA) stenoses and plaque morphology of the atherosclerotic lesions.

RESULTS

During the follow-up period (median 32 month, range 6-125 months) 7% of patients developed ischemic neurological events of which 1.7% was a stroke. Of these events, only 5.7% correlated with carotid lesions. The new neurological events correlated with the degree and progression of stenoses, with a non homogeneous echographic appearance and irregular surface. The progression of the degree of stenoses was the parameter that correlated the most with the development of new neurologic symptoms. Nevertheless, the lesions that progressed modified their echographic pattern from homogeneous to non homogeneous in 78% of cases. Irregular surface and high degree of stenoses more than the baseline echographic pattern seem to correlate with plaque progression.

CONCLUSION

Our follow-up study confirmed that ICA stenosis is a benign condition: very few strokes clearly correlated to the stenosis were observed. Nevertheless, the major predictors of risk for cerebrovascular events, besides the degree of stenoses, are the progression of the degree of stenosis, irregular surface and non-homogeneous echographic appearance.

Premature arterial and venous events in three families. Effect of folate levels and MTHFR mutation mediated by family/generation and homocysteine levels

Plasma homocysteine levels result from the effect of genetic and environmental factors. We investigated the hypothesis of familial association between folates, methylenetetrahydrofolate reductase (MTHFR) and hyperhomocysteinemia with acute events, studying three families through pedigree analysis and log-linear graphical models. In 43 subjects, 13 had homocysteine levels of >15 micromol/l. In Family A, premature venous and arterial events occurred in father and son, respectively. In Family B, several arterial premature events occurred and very high homocysteine level was found in a healthy 18-year-old nephew. In Family C, stroke occurred at the age of 16 in a boy. In all three families, all subjects with premature cardiovascular events had high homocysteine level as well as MTHFR mutation, either homozygous or heterozygous. The present results underline that hyperhomocysteinemia has a direct conditional association with cardiovascular events. Moreover, homocysteine level is a variable that links the indirect association of folates, MTHFR mutation and cardiovascular event.

Local photodynamic therapy with Zn(II)-phthalocyanine in an experimental model of intimal hyperplasia

Photodynamic therapy (PDT) appears to be a novel promising modality to prevent intimal hyperplasia (IH) and restenosis after angioplasty. Local PDT, that consists of local delivery of photosensitizing agents followed by intraluminal local irradiation, represents a recent advancement. This methodology requires optimization in order to achieve the best prompt outcome especially in terms of pharmacokinetics of the photosensitizing agent. We studied the pharmacokinetic properties by using the photosensitizing agent Zn(II)-phthalocyanine (ZnPc), locally released by a channeled balloon. The efficacy of local PDT in reducing IH was evaluated in an experimental rabbit model of arterial injury. The maximum accumulation of ZnPc was found at 30 min: the injured portion of the artery gave a ZnPc recovery of 1.18 micromol/mg, as compared with undetectable amounts of ZnPc in the non injured arteries; within 90 min after the local delivery, clearance of the agent was almost complete. Local PDT produced an effective reduction of IH in our vascular injury model: at 7, 14, 21 and 28 days IH and intima/media ratio (IMR) was significantly reduced as compared with balloon injured arteries. The local delivery of ZnPc showed favourable pharmacokinetic properties, that allow the performance of PDT immediately after the vascular injury. Local PDT performed in these conditions represents a promising approach to prevent IH after balloon injury. Further studies are needed to better clarify the biological response of the injured arterial wall to local PDT.

Evidence of postprandial absorption of olive oil phenols in humans

BACKGROUND AND AIM

Olive oil phenols are potent antioxidants in vitro. If this were to be also demonstrated in vivo, it would help to explain the beneficial effects of this typical ingredient of the Mediterranean diet. This study was designed to determine the presence in lipoprotein fractions of two phenolic compounds peculiar to extra virgin olive oil, namely tyrosol and OH-tyrosol, and whether their absorption induces an antioxidant effect in vivo.

METHODS AND RESULTS

Two trials were performed. In the first (Long-term), 14 healthy volunteers followed two diets, each for one month. The only difference between the diets was that the first supplied 50 g of extra virgin olive oil per day, where-as the second one supplied 50 g of refined olive oil with no simple phenols, as demonstrated by GC-MS analysis. There were no changes in LDL oxidizability and tyrosol and OH-tyrosol were not recovered in lipoproteins and plasma from fasting samples drawn at the end of each diet period. In the second study (Postprandial), eight healthy volunteers received an oral fat load consisting of 100 g of extra virgin olive oil. Blood was drawn at times 0', 30', 60', 120', 240', 360', and major plasma lipoprotein classes were separated. The concentration of tyrosol, OH-tyrosol and vitamin E was determined in lipoprotein fractions. Plasma antioxidant capacity was measured by a crocin-bleaching test and expressed as mM Trolox C equivalents. Tyrosol and OH-tyrosol were recovered in all lipoprotein fractions, except VLDL, with concentrations peaking between 60' and 120'. However, a very high variability in tyrosol and OH-tyrosol absorption was observed among subjects. Vitamin E content of LDL and HDL did not vary significantly throughout the study. Plasma antioxidant capacity increased significantly at time 120' (baseline 0.96 mM Trolox; 120' 1.19 mM Trolox; p = 0.02), and then returned almost to baseline values after 360' (1.1 mM Trolox).

CONCLUSIONS

These findings suggest that phenolic compounds in olive oil are absorbed from the intestine, though not through a pathway dependent on chylomicron formation, and may exert a significant antioxidant effect in vivo, probably in the postprandial phase.

[Extrahospital cardiac arrest: the experience of Mestre Emergency Service]

BACKGROUND

Out-of-hospital cardiac arrest (AC) is one of the leading causes of death in industrialized countries. AC-related mortality can be reduced by rapid intervention. We report the experience of the emergency medical service (EMS) of Mestre on the management of out-of-hospital AC.

METHODS

We analyzed 80 cases of out-of-hospital AC observed consecutively by the EMS of Mestre from February 1996 to September 1997: 72 cases (90.0%) involved cardiac etiology and 8 (10.0%) non-cardiac etiology. The 72 cases involving cardiac etiology were divided in three groups: group A) 12 unwitnessed ACs (16.7%); group B) 12 ACs witnessed by EMS personnel (16.7%); group C) 48 bystander-witnessed ACs (66.6%).

RESULTS

In group A, in which 4/12 patients (33.3%) presented ventricular fibrillation (FV) or pulseless ventricular tachycardia (TV) as initial rhythm, return of spontaneous circulation (ROSC) was obtained in one patient with FV and in one patient with asystole. In group B, 7/12 patients (58.3%) presented FV or TV as initial rhythm; in this subgroup, ROSC was obtained in 71.4% of cases (4 cases with FV and one case with TV) and discharge in 42.9%, while in the subgroup with other rhythms the rate of ROSC was 40.0% (two patients with pulseless electrical activity later died). In group C, 35/48 patients (72.9%) presented VF or TV as initial rhythm; in this subgroup, ROSC was achieved in 42.9% of cases (13 cases with FV and 2 cases with TV) and discharge in 14.3%, while in the subgroup of bystander-witnessed AC with other rhythms the rate of ROSC was extremely low (7.7%) (one patient with asystole later discharged). In group C, bystander cardiopulmonary resuscitation (CPR) was performed in 20/48 patients (40.1%). In these patients, FV or TV were more frequently recorded as initial rhythm (80.0 vs 67.9%; p < 0.05). In patients without bystander CPR, the interval between the time of collapse and the time of the first defibrillation was shorter in the patients who were admitted than in patients who died (6.0 +/- 1.4 vs 10.9 +/- 4.4 min; p < 0.05). Considering all patients with FV or TV as initial rhythm and the interval between the collapse and the first defibrillation exactly recorded, the percentage of ROSC decreased when the interval between the collapse and the first defibrillation increased.

CONCLUSIONS

Our data confirm that early defibrillation is the key factor in the prognosis of out-of-hospital AC. The data suggest that the immediate delivery of bystander CPR could extend the interval in which defibrillation is effective.

Percutaneous excimer laser angioplasty of lower limb vessels: results of a prospective 24-month follow-up

The aim of this prospective study was to assess the effectiveness and the long-term patency effect of excimer laser angioplasty in peripheral arterial obstructive disease. Seventy-eight patients referred for excimer laser angioplasty of lower limbs have been followed up for up to 24 months. Ankle/brachial systolic pressure index, color Doppler mapping, and arterial digital subtraction angiography were performed. Immediate procedural success was achieved in a high percentage of patients (97%). Balloon angioplasty was also used in 85% of patients. Early reocclusions occurred in 8% of patients. The cumulative patency rate was 47% at the 12-month interval and 40% at the 24-month interval. Poor runoff and the length of the lesions negatively influenced the outcome. Excimer laser angioplasty is an effective procedure, indicated in selected patients showing < 10 cm occlusions and good runoff.

[Prevalence of clinically silent pulmonary embolism in deep venous thrombosis of the legs]

BACKGROUND

Thromboembolic venous disease is a possible lethal condition which is very often present in clinical practice. The aim of this study was to evaluate the prevalence of clinically occult pulmonary embolism (PE) in a group of patients with recent proximal deep venous thrombosis (DVT), and the relationship between prevalence of PE and DVT extension, echographic features of the thrombi, anticoagulant therapy administered.

MATERIALS AND METHODS

The study enrolled 93 patients with DVT of the proximal lower extremities, without clinical symptoms and signs of PE. All patients were submitted to echo color-Doppler and ventilation-perfusion lung scan. The results were analysed by a score system for the echographic scan and by a series of probability criteria, as recommended by the PIOPED investigators, for the lung scan.

RESULTS

All patients were recognised to suffer from proximal DVT. High probability lung scans for PE were found in 43 subjects (46.2%), intermediate probability in 14 (15%), low probability in 7 (7.7%), very low-normal in 29 (31.1%). The prevalence of PE failed to show any significant difference with respect to DVT extension, ultrasonographic features of the thrombi and anticoagulant therapy administered.

CONCLUSIONS

The results obtained show a high prevalence of asymptomatic PE in patients with DVT, and suggest the need of an extensive use of lung scan in this kind of patients, and the utility of an early detection of DVT, in order to establish an intense antithrombotic therapy, irrespective of the extension of the thrombus with US.

The characteristics of the thrombi of the lower limbs, as detected by ultrasonic scanning, do not predict pulmonary embolism

OBJECTIVE

To evaluate whether pulmonary embolism (PE), as detected by perfusion lung scan, could be predicted by the ultrasonic (US) characteristics of the thrombi in patients with deep venous thrombosis (DVT) of the lower limbs.

PATIENTS

Ninety-three consecutive patients with DVT and no symptoms of lung involvement (52 men, 41 women; mean age, 67 +/- 17 years).

MEASUREMENTS AND RESULTS

The degree of thrombotic involvement of the lower limbs was assessed using a US score system ranging from 1 (indicating a subsegmental, nonocclusive thrombus) to 16 (massive, occlusive). According to the echographic and color-Doppler features, the thrombi were classified in terms of echoreflectivity, adhesiveness to the vein wall, and organization. The diagnosis of PE (PIOPED criteria) was highly probable in 46% of the patients, intermediate in 15%, low in 8%, and very low/normal in 31%. No correlations were found between the lung scan findings on one side and the venous scoring system or the US features of the thrombi on the other side.

CONCLUSIONS

While confirming that the prevalence of PE in patients with DVT is elevated, we failed to define a subgroup of patients at higher risk. Our data imply that lung scan should be used extensively for the detection of silent PE and that anticoagulation should not be graded on US findings.

[The prevalence of carotid and coronary diseases in asymptomatic patients at high risk for atherosclerosis]

To evaluate the prevalence of carotid lesions and silent coronary artery disease in asymptomatic patients, we studied 31 subjects with one or more risk factors for atherosclerosis. All patients have been studied by means of non invasive cardiologic evaluations and carotid echo color Doppler. The prevalence of carotid and or coronary artery disease was 80%. The prevalence of silent coronary artery disease was 19% and carotid artery disease 61%. Patients with more than one risk factor showed a higher prevalence of carotid lesions (84%) than those with only one risk factor (16%). In conclusion, the prevalence of carotid disease in asymptomatic patients, at risk for atherosclerosis, is high. The echo color Doppler system represents the best approach to study carotid atherosclerosis in vivo. When carotid lesions are present, a non invasive cardiological evaluation may be useful to reveal a silent coronary artery disease.

n-3 fatty acids do not enhance LDL susceptibility to oxidation in hypertriacylglycerolemic hemodialyzed subjects

Recent data suggest that treatment with n-3 fatty acids could enhance the susceptibility of plasma low-density-lipoprotein (LDL) to oxidation. Twelve hypertriacylglycerolemic, hemodialyzed patients were treated with 2.5 g n-3 fatty acids/d for 2 mo. Treatment was then withdrawn for 2 mo (washout phase). Plasma total cholesterol and LDL cholesterol increased significantly (9% and 28%) and plasma triacylglycerols decreased significantly after the n-3 phase compared with baseline and washout values. LDL susceptibility to oxidation was tested by oxidation of LDL particles with 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH). No significant changes were observed for the lag phase and the peroxidation rate. The vitamin E content of LDL also did not change significantly. The results thus suggest that a daily dosage of 2.5 g n-3 fatty acids does not enhance LDL susceptibility to oxidation, while retaining its hypotriacylglycerolemic effect.

Intimal medial thickening of common carotid artery as indicator of coronary artery disease

The authors investigated the relation between coronary atherosclerosis, angiographically detected, and intimal-medial (I-M) thickening of the common carotid artery (CCA), as measured by high-resolution B-mode ultrasound system. They studied 31 patients with coronary artery disease (CAD) and 23 healthy control subjects. I-M thickening of CCAs and atheromatous plaques at the carotid bifurcation were evaluated. A score system was defined (range 0-20) based on the absence or presence of atherosclerotic lesions at common and internal carotid arteries. A coronary angiography score was defined based on the presence of of atherosclerotic lesions at nine coronary arterial segments (range 0-36). The thickness of CCAs (M +/- SD) in CAD patients was significantly higher (1.45 +/- 0.95 mm) than in controls (0.87 +/- 0.10 mm, P < 0.005), and an I-M thickening of 1.1 mm or more was specific and positively predictive of CAD. A significant positive correlation between coronary and carotid score was observed (P < 0.028, r = 0.373). The study suggests that I-M thickening could be helpful for the identification of patients at risk for CAD.

Wall thickening of common carotid arteries in patients affected by noninsulin-dependent diabetes mellitus: relationship to microvascular complications

This study evaluates the wall thickness of common carotid arteries and the atherosclerotic involvement of the carotid bifurcations in patients with noninsulin-dependent diabetes mellitus (NIDDM), with and without microvascular complications. Seventy subjects affected by NIDDM, and 17 healthy controls were evaluated by means of high-resolution echo-Doppler scan. Twenty-six diabetics (Group A) and complications (overnight proteinuria > 500 mg, background retinopathy, sensory neuropathy), while 44 (Group B) had no complications. The two groups were comparable for age, sex, plasma lipid profile, and smoking habit. Arterial hypertension was present in 15 of 26 (58%) complicated patients (Group A) and in 18 of 44 (41%) uncomplicated patients (Group B). None of the patients had a history of cerebrovascular disease. The authors found that the wall thickness of the common carotid artery was greater and atherosclerotic lesions of the carotid bifurcation were more frequent in diabetic patients with microvascular complications than in uncomplicated diabetics (who had a similar distribution of other risk factors for atherosclerosis) and in nondiabetic controls. These data on the one hand confirm the role of diabetes as an independent risk factor for carotid atherosclerosis and, on the other hand, indicate a correlation between microvascular lesions and early atherosclerosis in diabetes.

Insulin action and glucose metabolism are improved by gemfibrozil treatment in hypertriglyceridemic patients

The aim of this study was to determine whether gemfibrozil-mediated decrease in very low density lipoprotein triglyceride (VLDL-TG) concentration is accompanied by an improvement in overall glucose metabolism in hypertriglyceridemic patients. We assessed this hypothesis in 7 hypertriglyceridemic without (HTG) and in 11 hypertriglyceridemic with noninsulin-dependent diabetes mellitus (NIDDM-HTG) who followed three-months treatment either with the drug or with placebo. Placebo VLDL-TG concentrations in both HTG (3.82 +/- 0.92 mmol/l (mean +/- S.D.) vs. 3.91 +/- 1.01 mmol/l) and in NIDDM-HTG (6.62 +/- 3.93 mmol/l vs. 6.84 +/- 4.16 mmol/l) were not different from baseline values, whereas gemfibrozil decreased VLDL-TG in both groups (1.84 +/- 0.56 mmol/l, P < 0.001 for HTG, and 1.93 +/- 2.68 mmol/l, P = 0.013 in NIDDM-HTG). In both groups, gemfibrozil treatment was associated with an improvement in fasting plasma glucose levels (from 5.85 +/- 0.92 mmol/l to 4.87 +/- 0.40 mmol/l in HTG, P = 0.001, and from 11.47 +/- 2.92 mmol/l to 9.56 +/- 3.41 mmol/l in NIDDM-HTG, P = 0.042). In NIDDM-HTG, gemfibrozil treatment was associated with a significantly lower 2 h-postprandial plasma glucose level (9.87 +/- 3.63 vs. 13.09 +/- 3.62, P = 0.05). A significant decrease in fasting free fatty acids (FFA) level was observed during gemfibrozil treatment in both groups, whereas in NIDDM-HTG, a significant drop of these substrates was observed in both fasting and postprandial conditions.(ABSTRACT TRUNCATED AT 250 WORDS)

Arterial mapping with color flow duplex imaging of the lower extremities after excimer-laser-assisted angioplasty

The purpose of the present study was to evaluate the role of color flow duplex imaging (CFDI) in the follow-up of patients who have undergone excimer-laser-assisted angioplasty of peripheral arteries. Sixty-one patients (40 men and 21 women) were studied (mean age +/- SD sixty-three +/- nine years). All patients were affected by peripheral vascular disease and, for this reason, underwent percutaneous excimer-laser-assisted angioplasty. Digital angiography and CFDI were performed before the laser procedure. CFDI was repeated at months 1, 3, 6, 9, and 12 after the laser procedure, whereas angiography was repeated after twelve months. Common, superficial, and profunda femoral arteries and popliteal arteries were visualized in looking for the presence of lesions and occlusions, and spectral analysis of Doppler signals was recorded. After the initial success, claudication was reported again by 9 patients, 7 of whom showed total occlusions. All reocclusions were discovered by CFDI and confirmed by angiography; 3 of these 7 patients underwent a second laser procedure. The remaining 2 symptomatic patients showed patent vessels and did not undergo angiography. Another 9 patients redeveloped an occlusion, unsuspected from clinical history and symptoms. All the reocclusions, confirmed by angiography, were diagnosed by CFDI. The data show that CFDI provides an accurate noninvasive technique for following up patients after excimer laser angioplasty, allowing for asymptomatic reocclusions to be recognized and treated if necessary, and permitting symptoms not due to reocclusions to be properly identified, thus avoiding unnecessary angiography.

Metabolic effects of dietary stearic acid in mice: changes in the fatty acid composition of triglycerides and phospholipids in various tissues

The fatty acid patterns of triglycerides and phospholipids extracted from adipose tissue, liver, heart, kidney, spleen, and lung of 3 groups of C57BL/6 mice were determined after feeding diets rich in palmitic acid (16:0) (high palmitic: 16:0 = 45.1% of total fatty acids), stearic acid (18:0) (high stearic: 18:0 = 42.9% of total fatty acids) and oleic acid (18:1) (high oleic: 18:1 = 79.7% of total fatty acids) for 9 months. Triglyceride content of adipose, liver, heart, kidney, lung and spleen tissues was significantly enriched in palmitic acid in mice fed the high palmitic diet (range among all tissues: 19.9% +/- 0.2% to 29.0% +/- 1.9% of total fatty acids) and in oleic acid in mice fed the high oleic diet (range 56.0% +/- 1.9% to 71.6% +/- 1.2%). The stearic acid content of organ triglycerides in mice fed the high stearic diet ranged from 3.7% +/- 0.3% to 10.8% +/- 1.2%; however, the content of oleic acid on this diet (range: 57.0% +/- 1.8% to 71.4% +/- 1.7%) was similar to the one observed in mice fed the high oleic diet. In all organs, phospholipids had a significantly higher percentage of stearic acid (range: 23.5% +/- 0.9% to 51.5% +/- 6.6%) than triglycerides, regardless of diet. To evaluate the production of oleate from stearate and palmitate, 2 groups of mice were fed the high palmitic and the high stearic diets for 1 week and then injected intravenously with [1-14C]palmitate and [1-14C]stearate and the amount of labelled oleate in liver triglycerides was measured.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of dietary monounsaturated and polyunsaturated fatty acids on the susceptibility of plasma low density lipoproteins to oxidative modification

Oxidized low density lipoproteins (LDLs) are thought to play an important role in atherogenesis. Nutritional and biochemical studies suggest that diet can modulate the susceptibility of plasma LDL to undergo oxidative degradation by affecting the concentration of polyunsaturated fatty acids and antioxidants in the lipoprotein particle. In the present study 11 healthy male volunteers underwent two diet phases. In one phase the diet was enriched in oleic acid (mono), while in the other it was high in linoleic acid (poly). Both diets lowered plasma total and LDL cholesterol contents. The sensitivity of plasma LDL to oxidation was estimated by challenging these lipoproteins with 2,2'-azobis(2-amidinopropane)dihydrochloride, a free-radical initiator. Although neither diet affected the antioxidant content of plasma LDL, the resistance to lipid peroxidation, measured after the consumption of antioxidants present in the lipoprotein, was higher during the mono phase. Indeed, the peroxidation rate of plasma LDL was inversely correlated with the oleic acid to linoleic acid ratio in the LDL particle. These results support the thesis that diets rich in monounsaturated fatty acids increase the resistance of plasma LDL to oxidative modification, independent of their content of antioxidants. This effect could lower the atherogenicity of these lipoproteins.

Carbohydrate and lipid metabolism in patients with non-insulin-dependent diabetes mellitus: effects of a low-fat, high-carbohydrate diet vs a diet high in monounsaturated fatty acids

Nineteen patients affected by non-insulin dependent diabetes mellitus (NIDDM), in good glycemic control (fasting plasma glucose 7.2 +/- 0.3 mmol/L, glycosylated hemoglobin 6.3 +/- 0.2%), underwent three isocaloric dietary phases. In phases 1 and 3 the diet was rich in complex carbohydrates (Carbo) whereas in phase 2 it was rich in monounsaturated fatty acids (Mono). Plasma glucose concentrations were 7.1 +/- 0.3 and 7.2 +/- 0.3 mmol/L for the two Carbo phases and 7.5 +/- 0.4 mmol/L for the Mono phase (NS). Plasma total cholesterol values for the Carbo phases were 6.2 +/- 0.2 and 6.4 +/- 0.2 mmol/L, respectively, and 6.5 +/- 0.2 mmol/L on the Mono phase (NS). Similarly, no significant changes were noticed for plasma triglycerides and high-density-lipoprotein (HDL) cholesterol. Thus, both diets were well-tolerated and did not alter glucose homeostasis or worsen plasma lipid concentrations. Consequently, these results suggest that a wider dietary choice can be made available to NIDDM patients without producing unwanted side effects.

Clinical follow-up and progression of carotid atherosclerosis determined by duplex scanning in patients suffering from TIA

We investigated the clinical outcomes and the progression of the internal carotid arterial lesions of a group of patients presenting with hemispheric TIAs. The cumulative frequency of TIAs during a mean follow-up period of 40 +/- 14 months was 14%, and no relationship was found between new TIAs and the presence of known cardiovascular risk factors or plaque characteristics as determined by duplex scanning. With the exception of one patient who died of stroke, none of the patients developed a permanent neurologic deficit. The cumulative death rate was 6.5%; myocardial infarction was the most common cause (3 out of 7). Anatomic progression of plaques was determined by duplex scanning in 22% of the internal carotid arteries. No relationship between progression of these plaques and the development of new TIAs was evident. We conclude that, in this group of patients, TIAs do not inevitably lead to stroke and that TIAs are not predictable based on risk factors or plaques characteristics.

Effects of dietary carbohydrates on metabolism of calcium and other minerals in normal subjects and patients with noninsulin-dependent diabetes mellitus

Transient hypercalciuria has been noted after high carbohydrate meals which is independent of dietary calcium and is probably due to impaired renal calcium reabsorption mediated by an increase in plasma insulin levels. Based on these observations, some investigators believe that long term intake of high carbohydrate diets may increase the risk of nephrolithiasis and possibly osteoporosis. Using a randomized cross-over design, we compared high carbohydrate diets (60% carbohydrate and 25% fat) with high fat diets (50% fat and 35% carbohydrate) for effects on metabolism of calcium and other minerals in eight normal subjects and eight euglycemic patients with noninsulin-dependent diabetes mellitus. All other dietary constituents, such as protein, fiber, fluid, minerals (including Ca, Mg, Na, K, and P), and caffeine intake, were kept constant. Despite higher daylong levels of plasma insulin on the high carbohydrate diets compared to the high fat diet in both normal and noninsulin-dependent diabetic subjects, no changes in daily urinary excretion of calcium or other constituents, associated with renal stone risk, were observed. Furthermore, there was no change in fractional intestinal 47Ca absorption. Although hypercalciuria may ensue transiently after high carbohydrate meals, we conclude that substitution of simple or complex carbohydrates for fats in an isocaloric manner for a longer duration does not result in significant urinary calcium loss, and therefore, high intakes of digestible carbohydrates may not increase the risk of nephrolithiasis or osteoporosis via this mechanism.

Intestinal absorption of stearic acid after consumption of high fat meals in humans

The intestinal absorption of stearic acid (18:0), relative to other fatty acids, was evaluated in a group of 10 normal volunteers. Subjects were fed two types of high fat meals; one contained a relatively high content of stearic acid and the other a relatively low content. Plasma chylomicrons were isolated at 2, 4, 6 and 8 h after ingestion of the meals. Fatty acid patterns of chylomicron lipids were determined, and relative intestinal absorption rates of each fatty acid were estimated by comparing the fatty acid composition of chylomicron lipids with that of the fat in the meals. Overall, for both meals the fatty acid pattern of chylomicron lipids was very similar to that of ingested fat. Percentages of palmitic acid (16:0) and stearic acid, relative to other fatty acids, were only slightly lower in chylomicron lipids than in the meal fat. These data suggest that intestinal absorbability of stearic acid is similar to that of palmitic acid, and both saturated fatty acids appear to be absorbed almost as well as oleic acid (16:1).

Food safety and health effects of canola oil

Canola oil is a newly marketed vegetable oil for use in salads and for cooking that contains 55% of the monounsaturated fatty acid; oleic acid, 25% linoleic acid and 10% alpha-linolenate [polyunsaturated fatty acid (PUFA)], and only 4% of the saturated fatty acids (SFAs) that have been implicated as factors in hypercholesterolemia. It is expressed from a cultivar of rapeseed that was selectively bred from old varieties in Canada to be very low in erucic acid--a fatty acid suspected to have pathogenic potential in diets high in the original rapeseed oil in experimental animals. Canola oil is free of those problems. It is the most widely consumed food oil in Canada, and has been approved for Generally Recognized as Safe (GRAS) status by the Food and Drug Administration (FDA) of the United States Department of Health and Human Services. The fatty acid composition of canola oil is consistent with its use as a substitute for SFAs, in meeting the dietary goals recommended by many health associations: an average diet containing about 30% of calories as fat made up of less than 10% SFAs, 8-10% PUFAs in a ratio of linoleic to linolenic acids between 4:1 and 10:1, the remainder being monounsaturated fatty acids. No single oil meets these current recommendations for ratios of PUFA/monounsaturated/polyunsaturated fatty acid ratios as the sole source of cooking and salad oil.

Comparison of a high-carbohydrate diet with a high-monounsaturated-fat diet in patients with non-insulin-dependent diabetes mellitus

We compared a high-carbohydrate diet with a high-fat diet (specifically, a diet high in monounsaturated fatty acids) for effects on glycemic control and plasma lipoproteins in 10 patients with non-insulin-dependent diabetes mellitus (NIDDM) receiving insulin therapy. The patients were randomly assigned to receive first one diet and then the other, each for 28 days, in a metabolic ward. In the high-carbohydrate diet, 25 percent of the energy was in the form of fat and 60 percent in the form of carbohydrates (47 percent of the total energy was in the form of complex carbohydrates); the high-monounsaturated-fat diet was 50 percent fat (33 percent of the total energy in the form of monounsaturated fatty acids) and 35 percent carbohydrates. The two diets had the same amounts of simple carbohydrates and fiber. As compared with the high-carbohydrate diet, the high-monounsaturated-fat diet resulted in lower mean plasma glucose levels and reduced insulin requirements, lower levels of plasma triglycerides and very-low-density lipoprotein cholesterol (lower by 25 and 35 percent, respectively; P less than 0.01), and higher levels of high-density lipoprotein (HDL) cholesterol (higher by 13 percent; P less than 0.005). Levels of total cholesterol and low-density lipoprotein (LDL) cholesterol did not differ significantly in patients on the two diets. These preliminary results suggest that partial replacement of complex carbohydrates with monounsaturated fatty acids in the diets of patients with NIDDM does not increase the level of LDL cholesterol and may improve glycemic control and the levels of plasma triglycerides and HDL cholesterol.

Olive-oil-enriched diet: effect on serum lipoprotein levels and biliary cholesterol saturation

The effect of diet enriched with a monounsaturated fatty acid (olive oil) on serum lipoproteins, biliary cholesterol saturation index, and gallbladder motility compared with a standard low-fat diet was evaluated in 11 young volunteers admitted to a metabolic ward. A significant decrease of mean total cholesterol (-9.5%), total apo B (-7.4%), LDL cholesterol (-12.2%), and total triglycerides (-25.5%) was observed after the olive-oil-enriched diet. Total HDL- and HDL-subfractions-cholesterol levels as well as serum apo A-I mean levels remained unchanged. Cholesterol saturation index of the bile and fasting and after-meal gallbladder volumes were unaffected by the enriched diet as compared with the low-fat diet. Olive oil may be a natural fat that can be used for the control of plasma and LDL cholesterol as a valid alternative to polyunsaturated fatty acids.

Effect of dietary stearic acid on plasma cholesterol and lipoprotein levels

We studied the metabolic effects of stearic acid (18:0) on plasma lipoprotein levels in 11 subjects during three dietary periods of three weeks each. The three liquid-formula diets, which were used in random order, were high in palmitic acid (16:0), stearic acid, and oleic acid (18:1), respectively. Caloric intakes were the same during the three periods. As compared with the values observed when the subjects were on the high-palmitic-acid diet, plasma total cholesterol decreased by an average of 14 percent during consumption of the high-stearic-acid diet (P less than 0.005) and by 10 percent during consumption of the high-oleic-acid diet (P less than 0.02). Low-density lipoprotein cholesterol levels fell by 21 percent in subjects on the high-stearic-acid diet (P less than 0.005) and by 15 percent in subjects on the high-oleic-acid diet (P less than 0.005). No significant differences were observed in the plasma levels of triglycerides or high-density lipoprotein cholesterol among the three diets. Measurements of the intestinal absorption of palmitic, stearic, and oleic acids revealed essentially complete absorption of each during the three dietary periods. The oleic acid content of plasma triglycerides and cholesteryl esters increased significantly during the high-stearic-acid period, suggesting that stearic acid is rapidly converted to oleic acid. We conclude that stearic acid appears to be as effective as oleic acid in lowering plasma cholesterol levels when either replaces palmitic acid in the diet.

Acromegalic cardiomyopathy. An echocardiographic study

Eighteen acromegalic patients (A) and 18 controls without clinical evidence of cardiac involvement and/or endocrine disease (C), matched for sex, age, body surface area, and blood pressure (BP), were investigated by M-mode (2-D derived) echocardiography, to clarify the prevalence and the possible determinants of left ventricular hypertrophy (LVH). Seven patients in each group were hypertensive (BP greater than 160/95 mmHg). Left ventricular mass (LVM) was 183.1 +/- 60.0 g/m2 in A and 130 +/- 25.9 g/m2 in C. A LVM above 140 g/m2 (that is the upper normal range in our laboratory) was found in 15/18 A and 2/18 C. The LVH was concentric (h/r greater than 0.45) in 12/15 A and 1/2 C. Systolic function indexes (% FS, end-systolic stress/end-systolic volume), cardiac index and total peripheral resistance index (as determined by echo) were within the normal range and similar in both groups. No correlation was found between LVM and BP, LVM and GH plasma levels, LVM and Sm-C levels. A significant correlation was found between LVM and duration of the disease (r 0.44; p less than 0.05). Our data confirm that LVH is an early and frequent finding in acromegaly. Its prevalence is not entirely accounted for by such factors as body size, BP or increased cardiac output. Metabolic factors may play a major role, and a long lasting exposition to increased GH levels seems the most relevant determinant of LVH.

[Incidence of aortic recoarctation in 161 patients after a mean follow-up of 8 years. The usefulness of pressure gradient measurement at rest and following exercise and of digital angiography]

The incidence of aortic recoarctation has been evaluated after a mean follow-up period of 8.2 years in 161 patients aged from 2 to 54 years at the time of the operation. To this aim, blood pressure levels in the upper and lower limbs were measured at rest and after bicycle ergometer exercise. Patients whose systolic pressure gradient was significant (either above 20 mmHg at rest or 35 mmHg after exercise) underwent aortic digital angiography. Aortic coarctation was diagnosed when the ratio of the aortic area at the site of the operation was less than 40% of that at diaphragmatic level (Frederiksen's index III). Thus the overall incidence of recoarctation was 10.1%. All patients with a significant gradient at rest also showed a significant gradient after exercise. This suggests that it is worthwhile performing digital angiography directly, without exercise testing, in these patients. However, 39.8% of the patients without significant rest gradients displayed a significant gradient after exercise. On the whole, only 21.4% of the patients with a significant gradient after exercise had signs of recoarctation on digital angiography.

Prevalence of atherosclerotic involvement of the internal carotid artery in hypertensive patients

The prevalence of atherosclerotic involvement of the internal carotid arteries, as diagnosed through an echo-Doppler imaging system with pulsed Doppler spectral analysis was evaluated in 49 hypertensives who had a negative history for neurological symptoms and 49 matched controls. The prevalence was 24.5% in the hypertensive group and 10.2% in the controls with a statistically significant difference (chi-square = 6.07, P less than 0.01). Two hypertensives had severe stenosis (above 50% diameter reduction) and 7 had potentially embolic lesions (irregular surface, inhomogeneous appearance). No one of the matched controls was as severely involved. We conclude that arterial hypertension can account for enhanced prevalence of carotid artery disease in asymptomatic patients.

Hemispheric TIA and amaurosis fugax: what is their relation to stenotic lesions of internal carotid artery?

We evaluated the correlation of clinical and echo-Doppler findings from the internal carotid artery (ICA) in 17 patients with amaurosis fugax (AF) and in 68 patients with hemispheric TIA (H-TIA). In the study population as a whole, moderate stenoses (20%-49% diameter reduction) were the most prevalent finding in the symptomatic ICA, being detectable in 51.6% of cases. Total occlusions were found in an unexpectedly high percentage (7.5%). Asymptomatic ICAs, that were contralateral to the symptoms, showed the same degree of atherosclerotic involvement as the symptomatic ICAs. When we compared AF with H-TIA, we found a significantly higher prevalence of severe hemodynamically significant stenoses in the former (52.6% vs. 18.8%, chi-square test 10.85, P less than 0.05). Thus, we conclude that in the vast majority of patients with transient neurological symptoms a bilateral ICA involvement is to be expected. The side on which the symptoms occur does not indicate which ICA is more severely stenotic except in AF, where a severe involvement of the ipsilateral ICA is most likely.

Apolipoprotein E polymorphism, serum lipids and occurrence of "double pre-betalipoproteinemia' (DPBL) in subjects from two different populations

The association between apolipoprotein E phenotype and the presence of 2 electrophoretic populations of very low density (VLDL) lipoproteins from human sera, double pre-beta(VLDL)lipoproteinemia (DPBL), was studied in 2 groups of subjects, one from Italy and one from Finland. In both populations the prevalence of DPBL was significantly higher in subjects with E4/4 and E4/3 phenotypes than in the other phenotypes not containing the E4 isoprotein. This finding suggests that the presence of a structural variant of the apo E protein, the isoprotein E4, may be causally related to the appearance of DPBL phenomenon.

[Prevalence, characteristics and clinical correlates of left ventricular hypertrophy in stable hypertension. Echocardiographic study]

251 in stable hypertensives were studied with M-Mode and two-dimensional echocardiography, in order to evaluate the prevalence of left ventricular hypertrophy (LVH), its patterns and clinical correlates. 54 subjects (21%) had been treated previously with antihypertensive drugs while the remaining 197 (79%) had not. A normal left ventricle was found in 69 subjects (27.1%; group A); a concentric LVH (h/r greater than or equal to 0.45) was found in 99 (39.4%; group B), while an eccentric LVH (left ventricular myocardial mass index greater than 140 g/m2, h/r less than 0.45) in 83 (43.1%; group C). An asymmetric LVH (septum to posterior wall thickness ratio greater than or equal to 1.3) was found in 33 subjects (3 did not fulfill the criteria for LVH, 21 had a concentric, and 10 an eccentric LVH). Mean age was significantly higher in group B as compared to groups A and C. The body mass index was comparable in all groups. Mean systolic blood pressure was significantly higher in groups B and C as compared to A. The duration and the severity of hypertension did not differ among the three groups. W.H.O. stage III was absent in group A, but no differences were found between group B and C as for W.H.O. stage distribution. We conclude that such factors as BMI, duration and severity of hypertension poorly correlate with the occurrence of LVH and its patterns. The fact that group B hypertensives were older than the others on average is against the hypothesis that eccentric hypertrophy follows the concentric pattern. Whether these two patterns represent separate entities in relation to different hemodynamic profiles deserves further investigation.

Echocardiographic evaluation of the dimensions and systolic properties of the left ventricle in freshman athletes during physical training

The purpose of the study was to evaluate the early anatomic and functional changes of the left ventricles in junior freshman non-professional athletes just beginning specific regular training programs for 6 different types of sport. Forty-nine males (mean age 20 +/- 6 years) and 9 sedentary controls were studied by means of sequential M-mode echocardiograms, before and after a 10 to 12 week training period: 13 athletes started bicycle-riding (aerobic category), 6 sprint (anaerobic category), 6 weight-lifting (strength category), 13 soccer (mixed category), 11 rifle-shooting (manual dexterity category). Resting heart rate, blood pressure, left ventricular diameter (LVID), left ventricular posterior wall and interventricular septum thickness (LVPWT, IVST), left ventricular mass (LVMI), relative wall thickness (h/r ratio) and fractional shortening (FS%) of the LVID, cardiac index (CI) and stroke volume (SV) were comparable in all groups initially. After the training period, the cyclists, the sprinters and the soccer-players showed an increased LVID, LVMI and FS%. The cyclists and the soccer players also showed a decreased h/r ratio. The weight-lifters showed a slight increase of their LVMI, with an increased h/r ratio. We have, thus, documented that even after a relatively short non-strenuous training period, specific anatomical and functional changes occurred in the hearts of young athletes practising sports for recreational purposes, according to the type of sport.

[Prevalence of atherosclerotic lesions of the carotid bifurcation found with echo-doppler (duplex) technic in patient candidates for aortocoronary bypass]

The association of an overt coronary artery disease with a cerebrovascular disease is frequently reported. However the real prevalence of atherosclerotic lesions at the carotid bifurcation in coronary patients is not well established. The aim of our study was to evaluate the prevalence of atherosclerotic involvement of the extracranial carotid arteries in a group of 141 patients undergoing coronary artery by-pass graft (CABG) and to verify whether any correlations between coronary and carotid artery disease exist. The extracranial carotid arteries have been studied by means of an echo-doppler (duplex) system, which combines a B-mode images with a pulsed doppler. A high prevalence (17.02%) of patients with a severe (greater than 50% diameter reduction) carotid involvement was detected (Tab. II). However, no correlations between the coronary and the carotid disease were found in terms of extension and severity (Tab. V). In conclusion, a systematic evaluation of the carotid arteries is recommendable in the coronary patients, candidates to CABG, even in the absence of cerebrovascular symptoms.

Prevalence of atherosclerotic lesions at the carotid bifurcation in patients with asymptomatic bruits: an echo-Doppler (duplex) study

The prevalence of atherosclerotic lesions at the carotid bifurcation with asymptomatic Meck bruits has been evaluated in 71 patients, 42 males, ages ranging from 19 to 84 yrs, referred to our non-invasive vascular laboratory for an echo-Doppler (duplex) scan, associated with spectral analysis (Mark V ATL with Flow analyzer 459). Fifty-nine patients had mid-neck or high-neck bruits (30 bilateral), 12 had low-neck bruits (4 bilateral). The internal carotid arteries were classified as normal, minimal stenosis (diameter reduction 20%), moderate stenosis (20-49%), severe stenosis greater than or equal to 50%), total occlusion. Twenty-four of the internal carotid arteries homolateral to a mid- or high-neck bruit were normal, 84% had stenosis of various degree (16% severe), 2% were occluded. Stenoses of various degree were also present on the contralateral side of the bruit. No lesions above a diameter reduction of 20% were present in the internal carotid arteries corresponding to a low-neck bruit. The echo-Doppler (duplex) system, being capable of spanning the whole spectrum of the internal carotid occlusive disease, allows us to limit the number of the invasive diagnostic procedures in asymptomatic patients.